Typically, vehicles and/or machines include a fuel-powered engine that may provide mechanical power to various transmission mechanisms. A transmission mechanism, such as a steering system, generally includes a driving member and a driven member. The driving member transfers the mechanical power from the fuel-powered engine to one or more loads, such as a steering load. An exemplary driving member may be a driving gear mounted to a driving shaft, and an exemplary driven member may be a driven gear in mesh with the driving gear and mounted to a driven shaft. The driving member may be continuously engaged with the driven member or selectively engaged with the driven member. The driving shaft may be rotated by the fuel-powered engine or an electric motor. Hence, rotation of the driving shaft may be transmitted to the driven shaft through the driving member and the driven member. In other words, the driving member transmits certain moment of force or torque to the driven member attached on the driven shaft. The driven shaft may be further connected to a load. For example, the driven shaft may be connected to a steering link of a vehicle. Hence, the driving shaft may transmit a torque to the driven shaft via the driving and the driven members.
Usually, the driving member and the driven member are designed to transmit the torque in a pre-specified range. In case the transmission mechanism experiences an excessive load, the driven member and/or the driving member may fail. In other words, gears of the driving member and the driven member may fracture when the load exceeds the tensile strength of the gear material. Load may also increase due to bearing seizure, any foreign material passing through the mesh of the gears, sudden failure of the engine, or mis-alignment of the gears. Also, if the torque transferred by the driven member and the driving member exceeds the pre-specified range, the complete transmission mechanism may fail.
One of the existing systems provides a keyway and key mechanism to prevent damage to gears in an event of excessive load. In such mechanisms a key is used to attach a rotating gear to a gear shaft. The key can be inserted in a key seat or keyway in the gear shaft. The keyway can be a grove or a pocket provided on the gear shaft such that the key can be fitted inside the keyway and the key can temporarily fasten the gear with the gear shaft. Hence, the keyway and key mechanism prevents any relative motion between the gear and gear shaft. Thus, in the condition of excessive load, the keyway or the key may shear. However in such a system, the gear and the gear shaft may need to be dis-assembled or replaced in an event of failure of the key or the keyway.